Post on 08-Apr-2018
8/6/2019 Notes Natural Selection September
1/76
The Theory of
Evolution
8/6/2019 Notes Natural Selection September
2/76
A theory
Explains the current observations andpredicts new observations.
Explains: Present day organisms are
similar, but not identical, to fossilorganisms.
Explains: Biodiversity
Explains: Populations are well suitedto their environments; molecules,organelles and cells specialized.
Predicts?
8/6/2019 Notes Natural Selection September
3/76
8/6/2019 Notes Natural Selection September
4/76
What is a species?
A speciesis a group of organisms that can mateand produce fertile offspring.
8/6/2019 Notes Natural Selection September
5/76
Are all dogs the same species with
variationsorarethey differentspecies ?
German Shepherd DachshundGreat Dane
Cana German Shepard and a GreatDanemateand produceoffspring ?
8/6/2019 Notes Natural Selection September
6/76
APuggle!!
8/6/2019 Notes Natural Selection September
7/76
ALaboradoodle. Of course.
So, dogs of different breeds are members of the same
species. They canproduce fertile offspring.
8/6/2019 Notes Natural Selection September
8/76
Variation and Adaptation
Populations are groups of organisms of the samespecies living together.
Variation exists among members of everypopulation
A population/species has adaptations for survivalin a particular niche
Whats the difference between variation and
adaptation?
8/6/2019 Notes Natural Selection September
9/76
8/6/2019 Notes Natural Selection September
10/76
forcapturinginsects
4)longstickytongue
8/6/2019 Notes Natural Selection September
11/76
Types ofA
daptationsAnything that helps an organism
Hide from/defend against predators
Attract a mate/reproduce (sexual selection)
Catch food
8/6/2019 Notes Natural Selection September
12/76
8/6/2019 Notes Natural Selection September
13/76
Attract a mate/reproduce
Male-male contest
Mate selection AnoleElephant Seal
Peacock
PeahenIrish Elk
8/6/2019 Notes Natural Selection September
14/76
Catch Food
8/6/2019 Notes Natural Selection September
15/76
Throughadaptations,populationsoftenbecomesuited toaspecifichabitatorniche.
Duck foot chickadee
8/6/2019 Notes Natural Selection September
16/76
Broadlyspeaking,a niche isahabitatandtheroleapopulationplaysinthathabitat.
8/6/2019 Notes Natural Selection September
17/76
Insect eaters
Bud eater
Seed eaters
Cactus
eater
Darwin &
Evolution by
Natural Selection
8/6/2019 Notes Natural Selection September
18/76
Beginninginthe late1700spaleontologistswerebeginningto discoverfossils of
animalsthatno longerexisted.
8/6/2019 Notes Natural Selection September
19/76
The irsts stemati explanati n ev l ti nasput rth by the Frenchscientist Jean-
Baptiste Lamarckin18 9. Inhistheory,Lamarck describedamechanism orevolutionknownas theinheritanceofacquired
characteristics.
Jean-Baptiste amarck (1774-1829)
8/6/2019 Notes Natural Selection September
20/76
Jean-Baptiste Lamarck
Lamarckbelieved thatfossilsofextinctanimals werethe
ancestors ofanimalslivingtoday.
8/6/2019 Notes Natural Selection September
21/76
8/6/2019 Notes Natural Selection September
22/76
3. Onceastructure wasmodified byuseor disuse,modificationisinherited byoffspring. Thisthird
principleiscalled the inheritance of acquired
characteristics
(Lamarkstated thatagiraffesneckgraduallybecame longerduetostretchingit duringits lifetime. Their longernecks
could thenbepassed ontotheiroffspring.)
8/6/2019 Notes Natural Selection September
23/76
Lamarkshypothesis
abouttheinheritance of
acquired
characteristicswas laterdisproved by
GermanbiologistAugust
Weismann
8/6/2019 Notes Natural Selection September
24/76
DespiteLamarckbeing wrong,thesearchforamechanismhad
begun.Theindividual tofinally discoverthe
mechanism
of
ev
olution
wou
ldbe . . .
8/6/2019 Notes Natural Selection September
25/76
8/6/2019 Notes Natural Selection September
26/76
Charles Darwin
Proposed a way how
evolution works
How did creatures change
over time? by natural selection
Collected a lot of
evidence to support hisideas
1809-1882
ritish naturalist
8/6/2019 Notes Natural Selection September
27/76
LaMarck
evolution by acquired traits
creatures developed traits
during their lifetime
give those traits to their
offspring
example
in reaching higher
leaves giraffes stretch their
necks & give the acquired
longer neck to offspring
not accepted as valid
Earlier ideas on Evolution
8/6/2019 Notes Natural Selection September
28/76
Darwins view of Evolution
Darwin
giraffes that already
have long necks
survive better leave more offspring who
inherit their long necks
variation
selection & survival
reproduction &
inheritance of more
fit traits
8/6/2019 Notes Natural Selection September
29/76
Robert FitzroyRobert Fitzroy
Voyage of the HMS eagle Invited to travel around the world
1831-1836 (22 years old!)
makes many observations of nature
main mission of theBeagle was to chartSouth American coastline
8/6/2019 Notes Natural Selection September
30/76
Voyage of the HMS eagle
Stopped in Galapagos Islands 500 miles off coast of Ecuador
8/6/2019 Notes Natural Selection September
31/76
GalapagosRecently formed volcanic
islands. Most of animals on
the Galpagos live nowhere
else in world, but they look
like species living on South
American mainland.
800 km west of Ecuador
8/6/2019 Notes Natural Selection September
32/76
Darwins journal givesa detailed descriptionofthehistoric journeyand hasbeenpublished as
"The Voyageofthe Beagle.
8/6/2019 Notes Natural Selection September
33/76
Manyof Darwins observations made
him wonder Why?
Darwin asked:
Whywere these creatures found only
on the Galapagos Islands?
Darwin foundmany unique
species
8/6/2019 Notes Natural Selection September
34/76
present day Armadillos
Darwin found:Darwin found:
Evidence that creaturesthat creatures
have changed over timehave changed over time
ancient Armadillo
Darwin asked:Darwin asked:
Why should extinctWhy should extinct
armadillos & modernarmadillos & modern
armadillos be found onarmadillos be found on
same continent?same continent?
Darwin foundclues in the
fossils
8/6/2019 Notes Natural Selection September
35/76
Darwin found:
Different shells on tortoises on different islands
Darwin asked:Darwin asked:
Is there a relationshipIs there a relationship
between the environmentbetween the environment
& what an animal& what an animal
looks like?looks like?
8/6/2019 Notes Natural Selection September
36/76
D
arwin found birds
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found:Darwin found:
Many different birds onMany different birds on
the Galapagos Islands.the Galapagos Islands.
He thought he foundHe thought he found
very different kindsvery different kinds
8/6/2019 Notes Natural Selection September
37/76
Darwin was amazed tofind out:
All14 species of birds
were finches
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found a lot offinches
Large ground
finchSmall ground
finch
Warblerfinch Tree finch
Butthere is only one
species of finch on the
mainland!
Darwin asked:Darwin asked:
If the GalapagosIf the Galapagos
finches came from thefinches came from the
mainland, why are theymainland, why are theyso different now?so different now?
8/6/2019 Notes Natural Selection September
38/76
8/6/2019 Notes Natural Selection September
39/76
Relationship between species (beaks) & food
8/6/2019 Notes Natural Selection September
40/76
Darwins finches
Darwins conclusions
variations in beaks
differences in beaks in the original flock
adaptations to foods available on islands natural selection for most fit
over many generations, the finches were selected for
specific beaks & behaviors
offspring inherit successful traits accumulation of winning traits:
both beaks & behaviors
separate into different species
8/6/2019 Notes Natural Selection September
41/76
Warbler finch
Woodpecker finch
Small
insectivorous
tree finchLarge
insectivorous
tree finch
Vegetariantree finch
Cactus finch
Sharp-beaked finch
Small
ground
finch
Medium
ground
finch
Large
groundfinch
Insect eaters
Bud eater
Seed eaters
Cactus
eater
variationnatural selection forbest
survival & reproduction
From 1 species to 14 species
8/6/2019 Notes Natural Selection September
42/76
Darwins Theory ofNatural Selection
1. There is variation withinpopulations. Somevariations are favorable.
2. More offspring are bornthan can possibly survivedue to limited resource.
3. Individuals that surviveand reproduce are thosewith favorable traits.
8/6/2019 Notes Natural Selection September
43/76
Natural Selection
variation Differences
in fitness
Changes in
a population
8/6/2019 Notes Natural Selection September
44/76
On
Nov
ember24,1 5 ,
Darwins
book,On theOriginof
Species is published.
8/6/2019 Notes Natural Selection September
45/76
8/6/2019 Notes Natural Selection September
46/76
8/6/2019 Notes Natural Selection September
47/76
Corn has been selected to produce
larger and larger ears over thepast 200 years.
8/6/2019 Notes Natural Selection September
48/76
All dogs breeds were created from wolves byhumans over a 10,000 year period.
8/6/2019 Notes Natural Selection September
49/76
Classification
Taxonomy: The scienceof naming organisms.
8/6/2019 Notes Natural Selection September
50/76
What variety! What similarity! Diversity of Life
there are so many different creatures onEarth
why are there differences? Unity of life
all creatures havesimilarities
common characteristics
why are they so alike?
8/6/2019 Notes Natural Selection September
51/76
Aristotle
Plant or animal?
If an animal, does it
Fly
Swim
Crawl
Simple classifications
Used common names
8/6/2019 Notes Natural Selection September
52/76
Carolus Linnaeus
Swedish botanist, 1750s Developed binomial nomenclature
First word = genus name
Second word = species name
Must be underlined or in italics
Genus capitalized
ex.Homo sapiens
8/6/2019 Notes Natural Selection September
53/76
Why binomial nomenclature?
Much easier than a 10+ word name under
old polynomial system
Less confusion
Binomial = SCIENTIFIC NAME
8/6/2019 Notes Natural Selection September
54/76
8/6/2019 Notes Natural Selection September
55/76
Organizing systems Making sense out of the differences
Eastern gray squirrel
Sciurus carolinensis
8/6/2019 Notes Natural Selection September
56/76
Taxonomic hierarchy Names organisms and their relationships
from very broad to very specific
8/6/2019 Notes Natural Selection September
57/76
8/6/2019 Notes Natural Selection September
58/76
How many are out there?
Scientists currently estimate that
There are 10 million species worldwide
Over 5 million live in the tropics
Most unnamed species are small or microscopic
8/6/2019 Notes Natural Selection September
59/76
Why is taxonomy useful?
Helps to show how organisms are related
Can be used to reconstruct phylogenies
evolutionary histories of an organism or
group
8/6/2019 Notes Natural Selection September
60/76
Cladograms Graph showing when different groups diverged
from a common ancestral line
Points where they diverge are often noted with a
feature that was different between ancestral group
and a new feature in the group that split off.
8/6/2019 Notes Natural Selection September
61/76
Phylogeneti Systemati s - Characters and Taxa
orangutan Gorilla Pan H. sapien
time
upright posture
use of tools
reduced
hairiness
bipedal
complexlanguag
The common ancestral
lineage to Pan (chimps)and H. sapien eventually
splits to form the
ancestors to
chimpanzees and H.
sapien.
8/6/2019 Notes Natural Selection September
62/76
How are Phylogenic Relationships
Determined?
D
NA
: a geneticcode
More closelyrelated organisms
have moresimilarities in theirDNA code
S
8/6/2019 Notes Natural Selection September
63/76
Structure
Closely related organisms may have similar
(homologous) structures, adapted to theirparticular niches
8/6/2019 Notes Natural Selection September
64/76
Embryology and Development
Closely related
organisms will have
similar embryo
development
8/6/2019 Notes Natural Selection September
65/76
Organizing the world of
organisms
The Tree of Life
organize creatures
by structure &function
how they are built
how they live
organize them intogroups of closely
related creatures
8/6/2019 Notes Natural Selection September
66/76
Three Domains, 6 KingdomsDomain Archaea
Contains 1 kingdom the Archaebacteria
Domain BacteriaContains 1 kingdom the Eubacteria
Domain Eukarya
Contains 4 Kingdoms:-Protista-Fungi-Animalia-Plantae
Prokaryotes
8/6/2019 Notes Natural Selection September
67/76
KingdomProtist
Kingdom
Fungi
Kingdom
Plant
Kingdom
Animal
KingdomArchaebacteria
KingdomBacteria
Prokaryotes
Eukaryotes
8/6/2019 Notes Natural Selection September
68/76
Bacteria
&
Archaebacteria
Classification
6 Kingdom system Prokaryotes
No separate organelles in their cells
Bacteria
Archaebacteria
Eukaryotes
Separate organellesin their cells
Protists Plants
Fungi
Animals
Prokaryote
Eukaryote
8/6/2019 Notes Natural Selection September
69/76
Prokaryotes Bacteria
one-celled organisms
microscopic
no organelles
have cell membrane have DNA
most common form of life on Earth
incredible number of different kinds
8/6/2019 Notes Natural Selection September
70/76
Archeabacteria
Ancient bacteria live in extreme environments
high heat
high salthot spring in which archaea
are found similar to bacteriabut have differentcell wall compounds
8/6/2019 Notes Natural Selection September
71/76
Prokaryotic = no
nucleus
DNA is not in a nucleus
as in eukaryotes.
plasmids are
small loops of DNA
cell wall composition determines gram-positive and
gram-negative types.TRUE BACTERIA -
MORPHOLOGY
Eubacteria
Most common bacteria,found everywhere!
8/6/2019 Notes Natural Selection September
72/76
Eukaryotes - Morphology
Nucleus
DNA organized
into chromosomes.
Many organelles(cell parts)
8/6/2019 Notes Natural Selection September
73/76
Eukaryotes can be unicellular or multicellular.
All have nuclei and organelles within cells.
Eukaryotes
Plants: autotrophic,
multicellular, cell
walls made of
cellulose
Fungi: heterotrophic,
decomposers, cell
walls made of chitin
8/6/2019 Notes Natural Selection September
74/76
ANIMALIA PHYLA
Porifera Cnidaria Platyhelminth AnnelidaM
ollusca Arthropoda Echinodermata Chordata
Animals: Multicellular, heterotrophic
8/6/2019 Notes Natural Selection September
75/76
Animals: Chordates
E k
8/6/2019 Notes Natural Selection September
76/76
EukaryotesProtists: Eukaryotic organisms that are less
organized than plants, animals, fungi.
Some are plant-like
Some are animal-like
Some are fungus-like
Slime mold
paramecium
algae